61 4door Fender bolts /nuts question

[61 Waycrosscomet]

So yeah, still bit of a newbie here even though working on car 6 years now. First thing I did was remove front fenders to get at suspension, etc. easier.
Didn't record or take good enough pics of the actual fender bolts. (now putting fenders back on)
I have on hand new fender bolts (wide thread), with U nuts, that I had ordered a fews years back.
My question: the new bolts I got are an inch and 1/8 long, The fine thread bolts (I beleive) that were on the car are an inch and 5/16th.

Do I need those longer 1" 5/16 bolts to secure the front fenders properly or will the shorter ones work? they will go through and grab the U nuts,
but not much bolt thread comes through the end of U nut.

seems like all the bolts I see for sale are the shorties, (as I call them).

one more question, does the front fenders require the long U nuts or will the short ones suffice?

thanks.
JohnM

[61 Waycrosscomet]

Never mind....I finally found someone on ebay who had the longer fender bolts with the proper dog teeth washer......